Electric current rectifier



UNITED STATES PATENT OFFICE ELECTRIC CURRENT RECTIFIER Emil Rupp, Berlin-Frohnau, Germany, assignor to General Electric Company, a corporation of New York Application October 11, 1932, Serial No. 637,355 In Germany October 14, 1931 14 Claims. (Cl. 175-366) My invention relates to electric current rectied in air at 950 C. and for a few minutes (three fiers of the dry plate or contact type, particuto five for example), after which the tungsten larly to rectifiers of this type comprising metalis quenched in water. The quenching makes it he elements having an active layer formed possible to obtain the blue layer alone, without thereon constituted by an oxide of the metallic the yellow oxide. The quenching itself can take element, and has for its principal object the proplace in heated water, or in heated as well as vision of a rectifier of high efliciency in which in cold oil. the active layer is constituted by a tungsten ox- 2. Blank tungsten in sheet form may be heated ide formed on a tungsten element. as in case 1 above, in a stream of nitrogen and A I have found that the blue tungsten oxide in a carbon-dioxide stream, after which it may which may be formed on tungsten metal at high be cooled in a stream of carbon-dioxide. temperatures possesses a high rectifying effect. 3. Blank tungsten in sheet form may be heated In accordance with my invention such a rectifyin oxygen at a reduced pressure, after which it ing substance is used in the making of dry recis quenched. n tifiers. 4. After undergoing any one of the processes The method of making the tungsten oxide recdescribed under cases 1 to 3 above, the blue layer tifier in accordance with my invention consists may be temp ed 01 treated at 300 to 600 C. in in heating blank tungsten at temperatures of an atmosphere which contains a slight amount 800 to 1200 C. in an oxygen-containing atmos- O y r st nce Carbon dioxide. 0 phere for a certain time. The blue tungsten oxt s to b n ted tha he tungsten Sheets may ide which is formed in this case has (in contrast be f rm d i a y suita l shap r xampl to the yellow tungsten oxide) a very pronounced e Sh ts may be cut into rings. rectifier efiect. Unlike other rectifier substances, When making e t fi s n accordance with this substance has a very slight internal resistmy v t n the pa nt m ta sh t f xid 25 ance, and t rectified r t are therefore coated tungsten serves as one electrode, and the '80 very hjgh other electrode may be made of any other metal. My invention will be better understood from Lead and Zinc are quite pp p r h a the following description when considered in con- Purpose Since iihey ay b sp yed O to th nection with the accompanying drawing and it oxide-coated tungsten sheet. The metal deposit 30 cope will be pointed t; in t appended claims. constituting this other electrode may be also of Referring to the drawing, Fig. 1 is a crosselectrolytic naturesectional view of a rectifier of the dry plate type In Order to Prevent a further Oxidation of the in accordance with my invention, and Figs. 2 blue tungsten layer, reducing m d a ay be used to 4 are cross-sectional views of modifications Such as lead Oxide and graphite- 35 of the invention. Insteadof using solid tungsten sheets, another m Fig 1 the rectifier t of t dry plate metal may be employed as a supporting sheet. type cgmprises a tungsten element plate 1, For example nickel sheets may be employed having thereon an active layer 2 of blue tungs which may be plated with tungsten, the tungsten ten oxide, and a conductive element or plate 3 layer then being fixidized to form the active 40 in contact with the oxide layer. In the present layerthereonembodiment of my invention the latter element P 15 to be noted that h i i i layer or plate is f rmed f lead hibits also a photo-electric sensitivity and may In Fig 2 the e tifier t is t Same as t be used as a back-wall as well as a front-wall unit illustrated in Fig. 1 except that in Fig. 2 the photocellconductive element or plate 4 in contact with the What I claim as new and desire to Secure y oxide layer is formed of zinc, Letters Patent of the United States is:

In Figs. 3 and 4 the rectifier units are the same h process f forming a y r ifier which as illustrated in Figs. 1 and 2 respectively except in lud s h at tun st n t a lativ ly hi h that in Figs. 3 and 4 the tungsten element 1 is t mp ratur t f m lu tu s n x d h r 50 in the form of a layer on a supporting sheet 5 and quenching said layer in water. of nickel or other suitable material. 2. The process of forming a dry rectifier which Following is a description of a few of the special c ud s heating tungsten t a relatively h methods which I have found suitable for the prop tu e to form a layer of blue n stenduction of the blue tungsten-oxide layer: xi h r n, a quenching Said l y r in Oil. 55 1. Blank tungsten in sheet form may be heat- 3- Th p ss of f min a dry r tifi r which '1 1o includes heating sheet tungsten in air for a few minutes at 900 C. to 1000 C. to form blue tungsten oxide on said tungsten, and quenching said tungsten.

4. The process of forming a dry rectifier which includes heating tungsten to a relatively high temperature in a mixture of nitrogen and carbon dioxide to form blue tungsten oxide on said tungsten.

5. The process of forming a dry rectifier which includes heating tungsten at temperatures between 300 C. and 600 C. to form a blue tungsten layer on said tungsten, and tempering said layer in an atmosphere having a relatively slight oxygen content.

6. The process of forming a dry rectifier which includes heating tungsten to a relatively high temperature in oxygen at reduced pressure.

7. A dry plate rectifier comprising a tungsten element having thereon a layer of blue tungsten oxide, and a metallic element in contact with said oxide layer.

8. A dry plate rectifier comprising a tungsten element having thereon a layer of blue tungsten oxide, and a lead element in contact with said oxide layer.

9. A dry plate rectifier comprising a tungsten element having thereon a layer of blue tungsten oxide, and a zinc element in contact with said oxide layer.

10. A dry plate rectifier comprising a tungsten element, a supporting element 01' another material for said tungsten element, a layer oi blue tungsten oxide on said tungsten element, and a metallic element in contact with said oxide layer.

11. A dry plate rectifier comprising a tungsten element, a supporting element 01 another material for said tungsten element, a layer of blue tungsten oxide on said tungsten element, and a lead element in contact with said oxide layer.

12. A dry plate rectifier comprising a tungsten element, a supporting element of another material for said tungsten element, a layer of blue tungsten oxide on said tungsten element, and a zinc element in contact with said oxide layer.

13. A dry plate rectifier comprising a tungsten element, a supporting element of nickel for said tungsten element, a layer of blue tungsten oxide on said tungsten element, and a lead element in contact with said oxide layer.

14. A dry plate rectifier comprising a tungsten element, a supporting element of nickel for said tungsten element, a layer 01 blue tungsten oxide on said tungsten element, and a zinc element in contact with said oxide layer.

EMIL RUPP. 

